Solanum rhaphiotes A.R.Bean, 2012

Bean, A. R., 2012, A taxonomic revision of the Solanum echinatum group (Solanaceae), Phytotaxa 57 (1), pp. 33-50 : 45-47

Solanum rhaphiotes A.R.Bean , sp. nov. ( Fig. 4 , 6B )

S. fecundo affinis sed ramulis ferrugineis aculeis paucioribus praeditis, pilis stellatis densissimis in pagina superiore folii, corolla minore et stylo erecto differens.

Type: — AUSTRALIA. Northern Territory: ca. 10 miles [16 km] W of the East Alligator crossing on the road to Oenpelli , 9 June 1971, D.E. Symon 7185 (holotype BRI!; isotypes CANB!, DNA! );

Illustration: Symon (1981: 197), as S. echinatum

Prostrate or sprawling shrub 0.1–0.5 m high and up to 2 m across. Adult branchlets rusty or brown; prickles 70–130 per decimetre, straight, acicular, 1–6 mm long, 7–11 times longer than wide, glabrous or with scattered stellate hairs near base; stellate hairs very dense, 0.3–0.6 mm in diameter, the stalks 0–0.25 mm long, the central ray 0.8–1.2 times as long as laterals. Adult leaves simple, the blades ovate to broadly ovate, 3.0– 7.9 cm long, 1.4–3.9 cm wide, 1.9–2.6 times longer than broad. Upper surface yellowish, prickles absent; stellate hairs very dense, ca. 0.05 mm apart, 0.35–0.5 mm across, stalks 0–0.2 mm long, central ray 0.7–1.0 times as long as laterals. Lower surface white or grey, prickles absent; stellate hairs very dense, spaced ca. 0.05 mm apart, 0.4–0.6 mm diameter, the stalks 0–0.3 mm long, the central ray 0.4–0.8 times as long as laterals; entire, the base obtuse or auriculate, the oblique part 1–4.5 mm long, obliqueness index 2–6 percent, apex acute; petioles 1.4–5.1 cm long, 34–67 % length of lamina, prickles present or absent. Inflorescence 3–6- flowered, with common peduncle 12–42 mm long, rachis prickles present; pedicels at anthesis 4–9 mm long, prickles absent or present; calyx tube 2.5–3 mm long, the lobes deltate, 1.5–3 mm long; calyx prickles absent or present at anthesis, 0–50 per flower, 0.5–4 mm long; calyx stellae very dense, brown or rusty, 0.4–0.6 mm across, the stalks 0–0.4 mm long, the central ray 1.0–1.4 times as long as laterals. Corolla purple, 7–11 mm long, the inner surface with a dense cluster of stellate hairs at each point; anthers 3.8–4.8 mm long; free part of the filaments ca. 1.1 mm long; style ca. 10 mm long, erect, protruding between anthers, glabrous. Fruiting calyx not completely surrounding fruit; stellate hairs all about the same size, the stalks 0.1–0.5 mm long, proto-prickles absent; prickles>100, 2– 7 mm long, straight, with stellae attached near the base; pedicels 12–17 mm long. Mature fruits 1–4 per inflorescence, oblate, size unknown.

Distribution and habitat: —Confined to the Kakadu National Park and Arnhem Land in the Northern Territory ( Map 3 ). It grows at the base of sandstone outcrops, or on sandy soil near sandstone pavement, and sometimes in rock crevices.

Phenology: —Flowers and fruits have been recorded from April to November.

Etymology: —From the Greek rhaphis —'a needle', and -otes —'special feature, characterised by'. This is a reference to the needle-like prickles on the fruiting calyx of this species.

Additional specimens examined (paratypes): — AUSTRALIA. Northern Territory: East Alligator River , 2 October 1946, S.T. Blake 17122 ( BRI); East Alligator R. near crossing, 23 June 1971, N. Byrnes 2192 (DNA); 23.5 km WSW of Twin Falls , 31 May 1980, L. Craven 6200 ( CANB); Alligator River , 1885, M.W. Holtze 567 ( MEL); Cannon Hill, 16 November 1972, J. McKean B822 ( CANB, DNA); East Alligator River , 4 km S of Cahills Crossing, 25 April 1987, J. Russell-Smith 556 (DNA); Oenpelli , 4 October 1948, R.L. Specht 1142 ( BRI); ca. 10 miles [16 km] SW of the Alligator River crossing to Oenpelli, 11 June 1967, D.E. Symon 5155 ( BRI, CANB, DNA); Adjacent to the East Alligator River crossing on the road to Oenpelli, 8 June 1971, D.E. Symon 7172 ( CANB, DNA); ca. 10 miles [16 km] W of the East Alligator crossing on the road to Oenpelli, 9 June 1971, D.E. Symon 7184 ( CANB, DNA); Arnhem Land, 16 km S of Yaimanyi Creek , 12 o 53’ 134 o 34’, 24 June 1972, D.E. Symon 7867 ( CANB, DNA); Arnhem Land, 6 km E of Alligator Crossing on road to Oenpelli , 28 June 1972, D.E. Symon 7968 ( BRI, CANB); Obiri Rock track, 4 km NW of East Alligator River crossing of Oenpelli road, 18 April 1980, I.R. Telford 7638 & J.W. Wrigley ( CANB); ca. 5 km S of Cahills crossing, East Alligator River, Kakadu National Park , 25 April 1983, H.S. Thompson 297 ( CANB).

Notes: — Solanum rhaphiotes is recognisable by its usually conspicuously rusty tomentum and prostrate habit. It is similar in leaf size and shape to S. lapidosum , but it differs in a number of ways (see notes under S. lapidosum ). It differs from S. fecundum by the rusty branchlets with fewer prickles, the very dense stellate hairs on the upper leaf surface, the smaller corolla, the erect style, and the oblate fruits.

Figures

MAP 3. Distribution of Solanum lucani (circles); Solanum rhaphiotes (triangles).

FIGURE 4. Solanum rhaphiotes. A. branchlet and leaves; B. a stellate hair from the branchlet; C. corolla and stamens; D. calyx, pedicel, ovary and style at anthesis; E. fruiting calyx surrounding dried fruit; F. a section of the fruiting calyx showing prickles and hairs. A–B from Russell-Smith 556; C–D from Byrnes 2192; E–F from Symon 7968. Scale bar: A = 12 mm, B = 0.25 mm, C = 3 mm, D = 2 mm, E = 6 mm, F = 1 mm.

FIGURE 6. Solanum hair types. A. section of fruiting calyx of S. echinatum showing prickles and hairs; B. section of upper leaf surface of S. rhaphiotes; C. a stellate hair from S. lucani; D. section of upper leaf surface of S. lapidosum. A from Harris 432; B from Russell-Smith 556; C from Thompson WES122; D from Fox 431. Scale bar: A = 2 mm, B = 0.3 mm, C = 0.25 mm, D = 0.3 mm.